Corona devices are known which are used in reproduction machines employing a photoconductive element to produce copies of documents to be reproduced. During reproduction processes such as xerography, it is necessary to apply charges to surfaces such as photoreceptor member or a copy sheet as part of the operation of the reproduction machine. For example, it is necessary to apply a uniform level of charge to the surface of a photoreceptor, which charge will subsequently be selectively dissipated by exposure to light. In xerographic processes, the non-discharged portions retain their charge in the form of a latent image on the photoconductive surface, and when subsequently brought into contact with toner material, will retain toner on the surface of the photoreceptor in the areas where the charge has not been dissipated. At a later time, a final support member, such as paper, transparencies, etc., may be brought into contact with the photoconductive surface, and a charge may be applied to the back side of the paper to attract the toner on the photoconductive surface to the support material. A detack arrangement may be provided to apply a neutralizing charge to the copy sheet to aid in its removal from the photoreceptor surface. A charge may be applied to the photoconductive surface as part of the removal of remaining toner from the photoconductive surface subsequent to transfer to clean the surface preparatory to reuse. The relatively large number of devices within a single machine require that the device be provided as inexpensively as possible.
In one type of preferred charging device, an electrically conductive electrode strip or coronode may be provided having projections, scalloped portions, or teeth members formed integrally with and extending from an edge of the strip. This arrangement has significant structural and operational advantages over other types of coronodes such as wires, including comparatively high structural strength and reduced undesirable ozone levels. In this respect, U.S. Pat. No. 3,691,373 to Compton et al. demonstrates a corona device generally comprising an electrically conductive electrode strip or pin array supported on either side by support strips, and held for use by a slotted member. The electrode is fixed into position by a plurality of transverse pins which fit through matching holes in the slotted member, pin array and support strips. An end portion is provided on one of the side strips for connection to an exterior connector from a high voltage source.
In copier manufacture, it is desirable to provide subassemblies within the copier to be constructed as simply and inexpensively as possible, while providing reliable operation. Additionally, since copiers tend to require a great deal of maintenance, subassemblies subject to regular maintenance requirements, such as the cleaning required for charging devices, should be easily removable and repairable, or inexpensive enough to simply discard if faulty or worn out. It is desirable when possible to make use of integral molded parts with a minimum of fasteners, and as few pieces as possible. Additionally, the assembly should be integrally provided with high voltage and assembly connectors to the main reproduction assembly so that it is easily inserted into position, it would also be desirable to provide a shield portion in close association with the assembly and provide the device with arc preventing features.